Serious program issues

Within the last few weeks I have started experiencing serious program issues…
for example I have 2 tabs/form pages open and am working on both back and forth editing the code in different events.
while running/testing one of the forms I start getting tons of errors…
After researching I find code from one tab/form has been copied to the other forms events…

Also I am having fields just disappear. I try to re sync the tables but it dose not add the field back… I have to delete the field from the DB then re-sync the table, re-add back to the db then sync the tables again…

Also I have had fields jump from one form to the other… for example I have 2 forms open and editing in different tabs… form 1 has name, address & phone in the DB and form… form 2 has the fields orderid, amount, date… after working for a while the name field will show in form 2 even though name is not in the table for that form and was never added manually by me…

Dose anybody have a suggestion, I have been using SC 9 for years without issue till recently…